Batteries for electric vehicles and the like, which are charged by chargers, have not only a load aspect of receiving power supply from chargers but also a power-supply aspect of supplying power to a variety of electric loads. Even in an abnormal state in which the temperature of batteries is out of a prescribed range, cooling devices such as fans for cooling batteries and other battery protection circuits operate, and therefore electric power is supplied to these circuits using batteries as power supplies.
However, if a battery is allowed to drive electric loads when abnormality of the battery is detected, charging power of the battery is wasted only for battery protection. As a result, considerable charging power has been consumed when the battery abnormal state is eliminated, and even if charging of the battery is resumed immediately after the abnormal state is eliminated, the charging time is prolonged to compensate for the consumed power.
Furthermore, some of electric loads that are essentially supplied with power of the charged battery are required to operate irrespective of the battery abnormal state. For example, in a case of automobiles, a variety of auxiliary equipment such as a light and an air-conditioner, which are connected as electric loads of batteries, may be required to operate regardless of the battery state. Therefore, when such electric loads start to operate, it becomes necessary to supply them with power from batteries, which is inconvenient in terms of charging.
Patent Publication No. 3247230 (Patent Document 1) discloses a charging control apparatus for an electric vehicle, in which when charging has to be interrupted temporarily depending on a battery state, power is supplied by a charger only by the amount consumed by auxiliary equipment such as a cooling fan, an air conditioner, and a light, based on a driving state of the auxiliary equipment, thereby suppressing battery power consumption.    Patent Document 1: Japanese Patent Publication No. 3247230